There has been a few reports of the iOS app growing larger and larger. Although the temporary folder should be cleared automatically by the system, however, we should try to clean up more proactively so users don't notice increase in app size before system's process kicks in, and we should, according to https://developer.apple.com/forums/thread/680224. For example, because mediaImporter works by moving all the imported photos to temporary directory, we need to make sure to delete those after done transferring them -- or skip this step entirely somehow?

As an extension, it might be helpful to introduce 1. a storage use breakdown visualization and 2. a clear cache button, although unnecessary if we get everything correct.